A three-phase motor can be operated in a star-configured circuit (Y circuit) and in a delta circuit. In a star-configured circuit, when the individual windings of each phase are connected in series this is referred to as a “star series circuit,” and when two individual windings per phase are connected in parallel, this is referred to as a “star double-parallel circuit” (cf. FIG. 15). When four individual windings are connected in parallel, this is referred to as a “star quad-parallel circuit.” Analogous terms that are used are “delta series circuit” and “delta double-parallel circuit” (cf. FIG. 3) or “delta quad-parallel circuit.”
In order to produce these different circuits, the winding ends of the individual coils must be interconnected in various ways; this requires a great deal of manual work. For example, in the case of the motor according to U.S. Pat. No. 6,177,741 B1, the stator of which is equipped with a star-configured circuit, the ends of the lacquered copper wires must be connected via soldered or crimped connections to the ends of flat conductors that are mounted on an insulating board. One of these conductors serves as a star point connector, and three other conductors serve as terminals for the U, V, and W phases. In motors for low power levels, it is also known to interconnect the ends of the individual windings using multi-layer circuit boards having printed circuits, although such designs are not suitable in cases where large currents must flow during operation.